Starter

Give the electronic configuration of an atom of:

- 94Be

- 2412Mg

- 4020Ca

Where are these elements found in the periodic table?

Forming Ions

Learning objectives• Demonstrate an understanding

that atoms of different elements can combine to form compounds by the formation of new chemical bonds

• Describe an ion as an atom or group of atoms with a positive or negative charge

Describe the formation of sodium ions, Na+, and chloride ions, Cl−, and hence the formation of ions in other ionic compounds from their atoms, limited to compounds of elements in groups 1, 2, 6 and 7

Explanation

Atoms are most stable when they have a f……… o…………… energy level of e…………………….Most atoms have to l………… or g………… electrons to do this.

Example on the board

Copy and complete

Atoms which have lost or gained

e…………………… are called

i……….

Metals

Sodium = 2311Na

1. Draw an atom of sodium, showing all of the electrons.

2. Will sodium lose or gain electron(s)? Draw the electronic configuration of the sodium ion.

3. Work out the charge on the ion.

More metals

Draw an atom of each of the following, showing the electronic configuration.

For each, work out how many electrons it loses. Draw the electronic configuration of the ion.

Work out the charge on the ion.

73Li

94Be

2412Mg

2713Al

Non-metals

Chlorine = 35.517Cl

1. Draw an atom of chlorine, showing all of the electrons.

2. Will chlorine lose or gain electron(s)? Draw the electronic configuration of the chlorine ion.

3. Work out the charge on the ion.

More non-metals

Draw an atom of each of the following, showing the electronic configuration.

For each, work out how many electrons it loses. Draw the electronic configuration of the ion.

Work out the charge on the ion.

199F

168O

3216S

147N

Extension

1. Explain why the group 0 elements do not lose or gain electrons.

2. From the work you’ve done today, can you figure out the formula of sodium chloride, magnesium chloride and aluminium chloride?

Learning check…• Demonstrate an understanding

that atoms of different elements can combine to form compounds by the formation of new chemical bonds

• Describe an ion as an atom or group of atoms with a positive or negative charge

Describe the formation of sodium ions, Na+, and chloride ions, Cl−, and hence the formation of ions in other ionic compounds from their atoms, limited to compounds of elements in groups 1, 2, 6 and 7